The invention relates to a system for controlling the operation of an automatic, variable speed transmission of the electronically controlled type in which the shifting of the transmission is controlled by a controlled energization of solenoid valves associated with a hydraulic control circuit of the transmission, and more particularly, to a control of the timing at which the solenoid valves are energized and deenergized during the shift operation.
In a vehicle having an automatic, variable speed transmission, the sudden release of the accelerator pedal while running in second gear could cause an automatic shift to third gear. During such a power off shift operation, percussion sounds in the drive train may be produced by the sudden reversal of torque.